Molding materials with a base of fatty acid-like properties produces mixed results. Most materials have a significant density difference between their solid state and the liquid state typically injected into molds. Chocolate products, for example, generally are prepared industrially by conching a ground chocolate ingredient mixture paste at a temperature of from about 50 degrees to about 85 degrees C. and by tempering the conched chocolate to provide a fluid, pourable mass. Viscosity considerations require that the fluid tempered chocolate generally be directed immediately to a molding operation for final product preparation. Although cooling can be carried out during tempering, correct tempering procedures generally require that the chocolate have a temperature on the order of from about 27 degrees C. to about 35 degrees C., depending upon the chocolate composition and character. In addition, when using tempered chocolate in a molding operation, temperature control of the mold also is important, and in general, heating and cooling operations are required.
If the mold temperature is less than the temperature of the tempered fluid chocolate being injected into the mold, the chocolate adjacent the mold surface tends to contract at a rate different from the remainder of the chocolate in the mold which, in turn, tends to result in rough product surfaces and/or de-molding problems and/or poor gloss. On the other hand, if the mold is too hot, the chocolate may lose its temper at least partially, which tends to result in poor contraction during cooling and/or in producing a product having a poor surface-finish. Thus, the molding operation generally requires heating a mold to a temperature which substantially corresponds to that of the tempered fluid chocolate.
After filling the mold cavity, the mold is cooled to set the chocolate. Generally, a cooling tunnel assembly or a multi-tier cooler, as known in the art, are used for this cooling. A properly set and glossy product typically requires cooling the mold and chocolate to a temperature on the order of from 10 degrees C. to 20 degrees C. The rate of cooling is also important, not only because of cooling contraction considerations, but also because an at least initial gradual controlled cooling should be employed so that the final product does not exhibit or tend to develop, prematurely, fat bloom. Thus, a cooling cycle time on the order of from about 20 minutes to about 30 minutes is typically required for a properly set product. This time frame limits the amount of production, while the equipment and energy necessary for thermal control increases the expense of product manufacture. Numerous materials other than chocolate, such as cheese, soaps, various candies and confectioneries, as well as intermediate fabrication processes that use wax of various forms, and the like, exhibit similar behaviors and have similar process requirements.